Berlusconi, who denies the charge, did not attend the opening session. The 77-year-old media mogul remains an influential political force in Italy despite being stripped of his Senate seat for a tax fraud conviction last fall. He still faces a prison sentence in that case, and a court is expected to assign him a year of community service after the original four-year sentence was reduced in a general amnesty.

The corruption case has ignited a new political storm in Rome after the Senate president announced the legislative body would seek to be a civil party in the case. Senate President Pietro Grasso has been accused of partisanship.

The court is expected to decide Wednesday whether to accept the Senate’s petition.

Also seeking to be a civil plaintiff in the case is the Italy of Values party, which politician Sergio de Gregorio bolted to join Berlusconi’s center-right party.

De Gregorio has acknowledged accepting the money between 2006 and 2008.